In Total Recall (1990), when checking his handwriting to see if it’s the same, Quaid’s pen at the hotel check-in is ironically red-capped but black-inked, a nod to the search for sameness and identity inside/beneath.

I'm not sure whether it's intentional or not, but it mirrors his search for who he really is "inside" and what his actual identity is, whether Quaid or Hauser and whether the events are real or just a dream. It's a small detail pointing to things not always being what they seem underneath.